| Abstract: | Abstract. Seed demography of three co-occurring Acer species in an old-growth mixed deciduous forest in Japan was studied. Almost all of the seeds of A. mono germinated in the first spring, while those of A. palmatum var. amoenum showed a delay in germination of almost one year. A. rufinerve showed a rather opportunistic germination habit. Both A. palmatum var. amoenum and A. rufinerve form short-term persistent seed banks, but without input of newly dispersed seeds they may become extinct in about one year. The seed bank for these two species is not as significant as for a typical pioneer species, and the seedling bank is important for all three species. Only a small proportion of the dispersed propagules contained viable embryos, mainly due to pollination failure or abortion (A. mono and A. palmatum var. amoenum), and invertebrate predation (A. rufinerve). For all three species, larger seed crops had a higher percentage of viable seeds. Even for these relatively small, wind-dispersed seeds, the predation pressure was very high. A large part of the dispersed seeds was eaten by wood mice during the first winter (30–80 %). Estimation from the 5-yr average of seed dispersal and seedling emergence showed that only 7–16 % of the dispersed viable seeds succeeded in germinating. |
